I would suggest a high velocity dog dryer, but that would be cost prohibitive in most cases. The only thing that I can think of is a shop vac set to blow. This would probably be a more economical route. I have very sandy soil, and my standard poodle loves to dig. She now is gray at the moment, when in reality she should be a light apricot

I used my little HV for dust. It is easy to damage eyes with blowing dust, be careful! Really it might be worth getting one as it blows out muddy feet really well too and of course gets a sopping coat damp dry in a few minutes.

A human style blow dryer cannot dry dog fur very well, could it blow out dust? Might try it to see if you don't have a wet dry you can clean out for the dogs. Careful with the eyes and ears though.